Investigate what effect different levels of concentration of sucrose solution have on the movement of water via osmosis in potatoes. EQUIPMENT Sucrose solution (0.2M, 0.4M, 0.6M, 0.8M, 1.0M) Distilled water (0.0M) Potatoes Cork borer Boiling tubes Boiling tube rack Stop clock Balance (0.0 decimal places) Tweezers Measuring cylinder Ruler METHOD Cut 6 pieces of potato with a cork borer and cut them to the same length of approximately 5 cm (measure with a ruler) Measure out 25cm³ of water and each of the sucrose solutions, using the measuring cylinder. The measurements for the solutions have to be perfect as to not change the outcome of the experiment. Pour into boiling tubes, giving the various concentrations. Label boiling tubes with concentration of sucrose solution Take measurements of each potato tube (mass) on the balance and record in a suitable table.
Minced potato provides a suitable source of catalase and the pH is varied in this experiment using citric acid-sodium phosphate buffer solutions at pH values of 4.4, 5.2, 6.5, 7.5 and 9. Hypothesis: As the value of pH increases, the amount of oxygen increases up to a point where the amount decreases. This is because the active site is denatured and the 3 dimensional figure is altered. Apparatus: • Citric acid-sodium phosphate buffer solutions of pH 4.4, 5.2, 6.5, 7.5 and 9 • Hydrogen peroxide solution • Potato • 10ml and 100ml measuring cylinder • Stopwatch • Stand and clamp • Water bucket • pH paper, pH meter and pH probe connected to data logger. • Cork borer • Large test tube • Rubber stopper and delivery tube Risk assessment/safety precautions Risk assessment Safety precautions Citric acid may be irritant Wear gloves, lab coat, and safety goggles Oxidising hydrogen peroxide is corrosive Wear gloves, lab coat, and safety goggles Fragile glassware eg measuring cylinder Place glassware in the middle of the table Variables: Independent variable: pH level Dependent variable: average volume of oxygen produced Control variable: Same size of potato, same amount of hydrogen peroxide.
OSMOSIS IN POTATO CELLS INVESTIGATION Introduction Osmosis is the passage of water from a region of higher water potential to a region of lower water potential through a partially permeable membrane. Osmosis only involves the movement of water molecules. The diagram depicts water molecules diffusing from the left hand side which has the higher water potential, to the right hand side which has the lower water potential. Only the water molecules can pass across the partially permeable membrane Figure 1 Aim The aim of this investigation is to record the effect of varying dilutions of sodium chloride solution on sections of potatoes and ascertaining the amount of osmotic activity between the two. The independent variable is varying the range of concentrations by diluting the 1M solution of sodium chloride.
Title: An investigation on the amount of diffusion by osmosis over 24 hours in differing sucrose concentrations upon potato cubes. Abstract: The experiment was conducted to examine the rate and effect of diffusion by osmosis on potato pieces with different glucose concentrations over a course of 24 hours. The initial and final weight of the potato was weighed in mg. Five groups containing three 2x1cm3 potato cores. The five groups of three potatoes were placed into separate beakers of distilled water that contained different sucrose concentration percentages (0%, 25%, 50%, 75%, 100%) and then left over 24 hours in order for osmosis to have time to pass through the potatoes thick membrane. The final weighing of the potato cores weighed less than initially since the water is leaving the potato in order to evenly distribute itself amongst the sucrose.
Record the results. 4) Potato and Peroxide- a small piece of potato and 2 ml of hydrogen peroxide. Record the rate of reaction. 5) Manganese dioxide and Peroxide- a pinch (tip of wood splint) of manganese dioxide to hydrogen peroxide. Record rate of reaction.
If our hypothesis is supported, our results will show that the higher concentration of salt, the faster the enzyme will denature. MATERIALS AND METHODS * 5 mL of potato extract * 10 mL of catechol * 3 mL of .1% salinity concentration * 3 mL of .9% salinity concentration * 3 mL of 2% salinity concentration * 3 mL of 5% salinity concentration * 3 mL of 20% salinity concentration * 1- 5 mL pipettes * Pi-pump for 5 mL pipette * Wax marker * 5 test tubes * Test tube rack My partner and I placed 1 mL of potato extract in five test tubes, along with 2 mL of catechol, to that we added 3 mL of .1% salinity concentration in tube one, 3 mL of .9% salinity concentration in tube two, 2% salinity concentration in tube three, 3 mL of 5% salinity concentration in tube four, and lastly 3 mL of 20% salinity concentration in tube five. Pour each mixture in it’s own spec 20 tube, along with a
This means that the potato that is dropped in water will have an increase in mass. This is because the potato already has all sorts of solutes in it, whereas the water doesn’t have any, making the concentration of the potato higher. Water will then flow into the potato to balance the water and potato’s solute concentration, which will increase the mass. This means that the potatoes in the 20% solution will have the opposite happen to them, now that it has solutes in it. This will lead to water diffusing out of the potato to balance the solute concentration of the water and potato, decreasing it’s mass.
6- Place only the edge of the Q-tip at the top the Flame. 7- Remove it when you see the of light being given off to avoid burning the Q-tip. 8- Clean up procedure: Discard used Q-tips to the bin, cover back compounds and put them up in a safe place, pour away distilled water in the sink, disconnect the Bunsen burner and clean it if stained,clean the lab test surroundings with paper towel to ensure no stain is left, wash your hands remove your goggles only when all equipments have been placed in safe places. Compound | Flame Colour Observation | 1 LiNO3
* 100% key lime * 50% key lime * 25% key lime 3. This is the formula to produce different key lime concentrations. * M1V1 = M2V2 Preparing of Kirby-Bauer test Materials and apparatus * Broth cultures of P. anvenginosa, E coli, S. aurens and B. spizizenii * Sterile cotton swab * Forceps * Bunsen burner * Whatman filter paper (small piece after punch) * Key lime discs * Parafilm Procedure 1. Swirl the contents of the broth culture of P. anvenginosa until it is equally murky throughout. 2.
Place the 5cm strip of tape on the bottom half edge of the Petri dish. Place the 100 kernels in the bottom half of the Petri dish. Notice that the 100 popcorn kernels are to represent 100 nuclei of atoms. Put the lid on the Petri dish and shake it around, make sure not to shake fast or hard. Put the dish on the flat surface and count out the popcorn kernels that are pointing to the 5cm masking tape.